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<DIV><FONT size=3>Chris:</FONT></DIV>
<DIV><FONT size=3></FONT> </DIV>
<DIV><FONT size=3>VERY true about the power supply. The range of the shunt
regulator was pretty narrow, and you could exceed it in either direction.
I've seen some running way too hot because of improper strapping. To
further confuse the issue though, there were some differences in how they were
wired through the years. Some of them "automatically" adjusted according
to jumpers that were located on the chassis of the load, in which case
unplugging the cable to the chassis would change the shunt value in the power
supply. </FONT></DIV>
<DIV><FONT size=3></FONT> </DIV>
<DIV><FONT size=3>Don</FONT></DIV>
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style="BORDER-LEFT: #000000 2px solid; PADDING-LEFT: 5px; PADDING-RIGHT: 0px; MARGIN-LEFT: 5px; MARGIN-RIGHT: 0px">
<DIV style="FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV
style="FONT: 10pt arial; BACKGROUND: #e4e4e4; font-color: black"><B>From:</B>
<A title=Chill315@aol.com href="mailto:Chill315@aol.com">Chill315@aol.com</A>
</DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A
title=quadlist@quadvideotapegroup.com
href="mailto:quadlist@quadvideotapegroup.com">quadlist@quadvideotapegroup.com</A>
</DIV>
<DIV style="FONT: 10pt arial"><B>Sent:</B> Thursday, February 10, 2011 11:14
AM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> Re: [QuadList] VTR introduction
anniversaries: 1965</DIV>
<DIV><BR></DIV><FONT id=role_document color=#000000 size=2 face=Arial>
<DIV>George</DIV>
<DIV> </DIV>
<DIV>Remember to change the strapping's on the 12 volt shunt regulator power
supplies. The power supply had to be strapped for the correct load or it
may go down. There is a procedure in the book that if we added
accessories, we had to change it. The one in the edit machine was
strapped differently so I had to make sure not to swap them.</DIV>
<DIV> </DIV>
<DIV>There were not tubes in the VR-1200 for the record amps. That was
an improvement that came along. Probably due to improvements in
transistor capabilities at the frequencies required. The 1200 pre-amps
were transistorized. It was interesting how AMPEX did the bit with the
same MK-X head for different series machines by just having interchangeable
pre-amps.</DIV>
<DIV> </DIV>
<DIV>Chris Hill</DIV>
<DIV>WA8IGN</DIV>
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